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Seeking information on CAC hoses
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My bad. I saw that and thought it was a black and white photo.
I’m dialing the local crow dinner shop now, but can we agree at least that there is no blue hose acceptable for the hot side?
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After several phone calls, lots of time on hold, getting cut off once, and getting piecemeal information I have no information I consider solid enough to state as fact.
But I did gather part of the information that will require someone to verify in person, but I have enough confidence in to make and educated guess.
Forget the service bulletin because it expired and it has outdated part numbers. Some of the bulletin appears correct. For example, the 531469 part numbers for the cold side, that is from the CAC outlet to the intake manifold seems to be blue hoses based on the price of $34.50 each. However Prevost also offers an alternative which is Volvo part number 21448469 which from its $169.78 price tag suggests it is the red hose that would be better for the turbo to the CAC inlet.
The part number 531467 called for at the turbo is priced at $52.10 and it may be a red hose or blue. I tried to talk to guys in the Nashville parts department so they could actually put an eyeball on the part but the Prevost phone system makes it difficult if not impossible to talk to someone who can actually look at the part.
The CAC inlet hose in the bulletin calls for 531396, but that is now superceded by 531471, priced at $27.83 which sounds like a blue hose price.
My suggestion is simple…….if you swap out a charge air cooler, or want to replace hoses simply state you want red ones for the hot side and blue ones for the cold side. Accept nothing else. These hoses were characterized as being heavily ordered which I presume was because of failures. When I spoke in terms of replacing hoses as preventive maintenance it was stated as being a good idea based on the number of hoses ordered from the parts guys in Elgin.
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Yes Jon, I agree 100% there is no blue hose acceptable for the hot side that I can find. And like you suggested we should not accept a blue hose anywhere other than the cold side.
Bill S.
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Without taking stuff apart I cannot do a good job of showing the “red” and “blue” hoses being discussed. This photo shows the turbo with the red hose attached.
The turbo outlet enters the red hose and from that point there is a metal tube that goes to the inlet (bottom) of the CAC. The connection at the tube to the CAC should also be a red hose. The turbo is located on the driver’s side of the engine. From the turbo to the CAC lower fitting is called the “hot” side.
Above the turbo is the blue hose which is part of the tubing assembly which goes from the top (outlet) of the CAC, across the top of the engine and to the engine intake manifold on the passenger side of the engine.
If you look at the article (link in a previous post) you will see an illustration that depicts the hoses, tubes, and how they are part of the air cooling system.
A different view of the turbo. If you have a blue hose where the red hose is in this and the above photo the probability that hose will fail is high. When it fails you lose turbo boost and your bus will barely move under its own power.
At the very least the turbo outlet requires a red hose, and it is strongly suggested the other end of the the tube from the turbo going to the CAC inlet also should have a red hose. There is a removable panel behind the tag tire that will allow access to the lower CAC fitting and hose. If you have red hoses on the “cold” side which in the photos above has the blue hose those are OK. The cold side hoses can be blue (much cheaper) or red (very expensive). Make sure all hoses are double clamped on each end.
If you have Prevost make this repair to insure your hoses are rated for the temperatures they will be exposed to they may tell you it is OK to put blue hoses on the hot side, or that you need red hoses for the cold side. Do not allow yourself to be bullied into accepting what may still be shown on the parts lists or bills of material. If you do have that conversation please report it here and document your chassis year, the service center location, and any other information you wish to provide.
BTW, this only applies to EGR equipped coaches, chassis year 2004 and up.
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Jon,
Thank you very much for the photos… They as well as your explaination are very helpful. I will confirm what I have but I am pretty certain I fall into the category of went to Prevost and asked for the correct thing yet still got the wrong thing. So given the attention Karl is bringing to this discussion, I am hoping that someone at Prevost will step up and correct my situation before I find myself of the side of the road. It’s happened once and really wasn’t a lot of fun. Karl, Jon should I contact Guy directly or would you prefer to roll me into the discussion you are going to have? -
I have had conversations with Guy French and the nicest way to say it was that the conversations were not productive.
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A view of the tubes with cooling package and CAC removed. 2005 XLII
Note; left of fan a panel has been removed located behind the tag wheel which allows access to hoses.
Cooling package just as it was removed from bus, radiator left, CAC right. 2005 XLII
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Notice on Al’s photo above of the blue tubes on the CAC fittings. The blue tube on the bottom should be red. That is the hot side.
Al went through a lot of grief about the hoses used on his coach, now owned by others.
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Jon,
I just checked my invoice and I have Volvo part number 21448469 I am going to check now but I am nearly positive that is a blue hose… so if that is the case even at the $151 price should it be replaced?Bill
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Yes Bill replace with red hose
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Guys,
Anyone have a valid prevost part number for the “red” Hoses? Going into the shop on thrusday to get them swapped and nobody at Prevost can confirm a correct part number for a red hose. Kevin Laughlin from prevost is looking into for me. He told me they are no longer using red hoses that everything they use is Blue.. Don’t kill the messenger but that is what they told me. -
At the risk of beating this issue to death let my concerns be completely clear. I am not going to power coat this with sugar.
When this began Al (BA or boateral) posted photos of the CAC replacement and I noticed the blue hoses were used on the hot side (exposed to 500 degree temps) and red hoses were used on the cold side (rated for 500 degrees, but only exposed to a couple of hundred degree temps. The blue hoses exposed to the hot temps were about 1/3 the price of those installed on the cold side which made no sense at all. It was an engineering error that transposed the numbers and because the documents were the only thing the Prevost techs could go by they insisted they were right. I finally spoke that morning to Bill Jensen and he appeared to agree with me and he authorized the hoses be reversed. He also indicated engineering would be notified of the error, but it might take a couple of weeks to issue the revisions.
Fast forward since then……Apparently either the engineering revision has not been made or force of habit is causing folks at Prevost to insist blue hoses can be used on the hot side.
I know the air temp from the turbo when the EGR is functioning reaches 500 degrees. I have monitored that with my DDEC reader so unless Kevin or anyone else can prove to you the blue hoses have a 500 degree rating they are full of shit saying blue hoses are OK. I have never been able to find any blue hose from any supplier that rates the hose at greater than 350 degrees.
My concern is the technicians and sadly Kevin Laughlin are not investigating this issue sufficiently to understand the hot side not only sees 500 degrees, it also is at 50 PSI. That is a lot of pressure and when combined with the high temps is a very hard strain on any hose. Failure to use a sufficiently rated hose will result in a failure. Based on my conversation yesterday with the parts folks in Elgin their records indicate the usage on the hoses is higher than they expected. I’ll bet that is due to inappropriate useage.
In my post above the 8 digit Volvo number (and high price) is for a high temp hose I believe.
Anybody getting the hoses changed can expect resistance if asking for red hoses at the turbo and CAC inlet (the bottom fitting) but since I learned while eating my dinner of crow, red is not the only high temp color, but it is likely the only high temp color stocked by Prevost. Demand it on the hot side. Do not be badgered, bullied or fed a line of crap by anybody. Insist on red. Double clamp the hoses. If you want to do a little overkill use them on the cold side, but blue is more than adequate for the cold side.
Between Karl and I who worked independently of one another and at different times it appears we are wasting our breath talking to Prevost, no matter how high up the food chain we go. If you do get hoses changed, and you do end up with blue ones on your EGR equipped coach on the hot side, you will have time to send us a report on how that worked out while you are sitting on the side of the road awaiting the tow truck.
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Jon,
Sorry to kep adding to the pain here…. I have a volvo part 21448468 on my bus but it isn’t red. All my hoses are Blue.
The prevost shop that saved my butt last week on the bearings called prevost as well and has ordered all the hoses I need but said he isnt sure of the color they are as prevost couldn’t tell them.
So if no body has a part number on the red hoses not sure what I can do.
In checking this out today I noticed that one of my pipe brackets broke and the upper hose clamp is rubbing thru the lower hose so the fun never ends. -
What about a Volvo truck shop? I presume some models at least use the same engine/CAC set-up. As I mentioned in an earlier post, Volvo truck spares specialists all list red hoses for the hot side.
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